Structure for holding battery of electronic timepiece

ABSTRACT

To provide a battery holding structure of an electronic timepiece having a simple constitution and being inexpensive, there is provided a battery frame ( 102 ) having an opening portion ( 113 ) for holding a battery ( 101 ), the battery frame ( 102 ) is provided with engaging portions ( 105  through  108 ) projected to a side of the opening portion (113) and having eaves portions ( 105   a  through  108   a ) provided with tapers and the battery ( 101 ) is inserted into the opening portion ( 113 ) and is held by the battery frame ( 102 ) and the eaves portions ( 103   a  through  109   a )

TECHNICAL FIELD

[0001] The present invention relates to a battery holding structure forholding a battery in an electronic timepiece.

BACKGROUND OF THE INVENTION

[0002] Conventionally, in an electronic timepiece of a digital displaytype or an analog display type, a battery is used as a drive source.Conventionally, as a method of attaching a battery to a timepiece mainbody, the battery is integrated to the timepiece main body andthereafter, the battery is held by using a separate member for holdingthe battery such as a battery holder.

[0003]FIG. 6 and FIG. 7 show a battery holding structure of aconventional electronic timepiece using a battery holder. Here, FIG. 6is a plane view of a periphery of a battery holding structure, FIG. 7 isa front sectional view of a D-D portion of FIG. 6 and the same notationsare attached to the same portions.

[0004] In FIG. 6 and FIG. 7, numeral 401 designates a battery, numeral402 designates a battery frame made of resin having an opening portionhaving a diameter slightly larger than that of the battery 401, numeral403 designates a battery holder made of a metal constituted by a memberseparate from that of battery frame 402, numeral 404 designates an eavesportion integrally formed with the battery frame 402 and numeral 405designates a positive electrode terminal. When the battery 401 isattached to inside of the battery frame 402, the battery 401 iscontained in the opening portion of the battery frame 402 to dispose ona lower side of the eaves portion 404 and thereafter, the battery holder403 is attached to the battery frame 402 from an upper side of thebattery 401. Thereby, a positional shift of the battery 401 in a planedirection is prevented by the battery frame 402, further, the battery401 sandwiched by the battery frame 402, the battery holder 403 and theeaves portion 404 and a positional shift in a sectional direction anddetachment of the battery 401 are prevented. Further, under the state,the battery 401 is held in a state of being brought into electricalcontact with the positive electrode terminal 405 and a negativeelectrode terminal (not illustrated).

[0005] As described above, by using the battery holder 403, the battery401 can be held.

[0006] However, according to the above-described structure, in order toprevent the battery 401 from moving in the sectional direction, there isneeded the battery holder 403 which is a part separate from the batteryframe 402 and there poses a problem a number of integrating steps isincreased and the constitution becomes complicated and expensive.Further, there poses a problem that a thickness of the electronictimepiece is thickened since the battery holder 403 is arranged tooverlap the battery 401.

[0007] It is an object of the invention to provide a battery holdingstructure of an electronic timepiece which can be constitutedinexpensively by a simple constitution. Further, it is another object ofthe invention to be capable of thinning an electronic timepiece.Further, it is another object of the invention to be capable of holdinga battery firmly such that the battery is not positionally shifted evenwhen an electronic timepiece is dropped.

DISCLOSURE OF THE INVENTION

[0008] The invention adopts a technical constitution described below toachieve the above-described object.

[0009] That is, according to an aspect of the invention, there isprovided a battery holding structure of an electronic timepiececharacterized in comprising a battery frame having an opening portionfor holding a battery, wherein the battery frame is provided withengaging portions projected to a side of the opening portion and havingeaves portions provided with tapers. The battery is inserted into theopening portion and is held by the eaves portions of the engagingportions.

[0010] Here, there may be constructed a constitution in which aplurality of the engaging portions are provided and the eaves portionsof the engaging portions are provided with the tapers in shapes by whichwhen the battery is attached, the battery is brought into contact withnarrow width portions of the eaves portions and thereafter brought intocontact with wide width portions thereof.

[0011] Further, there may be constructed a constitution in which theengaging portions are constituted by the eaves portions and arm portionshaving an elasticity for attaching the eaves portions to the batteryframe.

[0012] Further, there may be constructed a constitution in which thebattery frame and the engaging portions are integrally molded by aninsulating resin.

[0013] Furthermore, there may be constructed a constitution in which theeaves portions are integrally formed with projected portions which arebrought into contact with a case back in a state of being mounted withthe case back.

[0014] Further, there may be constructed a constitution in which atleast portions of the projected portions are constituted to project tothe side of the opening portion more than inner wall faces of theengaging portions and are brought into contact with the case back atpositions projected to the side of the opening portion more than theinner wall faces.

[0015] Further, the battery may be a button battery.

[0016] Further, the electronic timepiece may be an electronicwristwatch.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017]FIG. 1 is a plane view showing a specific example of a batteryholding structure of an electronic timepiece according to the invention.

[0018]FIG. 2 is a partial front sectional view showing the specificexample of the battery holding structure of the electronic timepieceaccording to the invention.

[0019]FIG. 3 is a front sectional view showing a mode of use of thespecific example of the battery holding structure of the electronictimepiece according to the invention.

[0020]FIG. 4 is a plane view showing other specific example of a batteryholding structure of an electronic timepiece according to the invention.

[0021]FIG. 5 is a partial front sectional view showing the otherspecific example of the battery holding structure of the electronictimepiece according to the invention.

[0022]FIG. 6 is a plane view showing a battery holding structure of aconventional electronic timepiece.

[0023]FIG. 7 is a partial front sectional view showing the batteryholding structure of the conventional electronic timepiece.

BEST MODE FOR CARRYING OUT THE INVENTION

[0024] A detailed explanation will be given of specific examples ofbattery holding structures of an electronic timepiece according to theinvention in reference to the drawings as follows.

[0025]FIG. 1 is a plane view showing a specific example of a batteryholding structure of an electronic timepiece according to the invention,showing an example of an electronic wristwatch. Further, FIG. 2 is afront sectional view taken along a line A-A of FIG. 1. Further, in FIG.1 and FIG. 2, there is shown a state of holding a battery in a batteryframe and the same portions are attached with the same notations.

[0026]FIG. 1 and FIG. 2, numeral 101 designates a button battery whichis a kind of battery, numeral 102 designates a battery frame made ofinsulating resin having an opening portion 113 having a diameterslightly larger than that of the battery 101, numerals 103 through 109designate a plurality of engaging portions constituted by moldinginsulating resin integrally with the battery frame 102, numeral 110designates a positive electrode terminal, numeral 111 designates anegative electrode terminal having elasticity urged to project from ahole 112 formed at a bottom portion of the battery frame 102 and numeral114 designates a winding stem.

[0027] The engaging portions 103 through 109 are constituted by eavesportion 103 a through 109 a projected to sides of the opening portion113 for preventing positional shift in a sectional direction ordetachment of the battery 101 and arm portions 103 b through 109 bconnecting the eaves portions 103 a through 109 a to the battery frame102 and having elasticity for restricting positional shift of thebattery 101 in a plane direction.

[0028] The eaves portion 105 a through 108 a of the plurality ofengaging portions 105 through 108, are provided with tapers in shapes bywhich when the battery 101 is attached, the battery 101 is brought intocontact with narrow width portions 105 c through 108 c of the eavesportion 105 a through 108 a and thereafter brought into contact withwide width portions 105 d through 108 d thereof.

[0029] Further, the eaves portion 109 a of the engaging portion 109 isnot provided with taper. Further, although the eaves portion 103 a and104 a of the engaging portions 103 and 104 are provided with tapers andrespectively formed with narrow width portions 103 c and 104 c and widewidth portions 103 d and 104 d, at an initial stage of attaching thebattery 101, one end portion of the battery 101 is inserted into lowersides of the eaves portion 103 a and 104 a and therefore, it is notnecessarily needed to provide the tapers to the eaves portions 103 a and104 a.

[0030]FIG. 3 is a front sectional view showing a mode of use when thebattery 101 is attached to inside of the battery frame 102, showing asectional view in correspondence with a B-B section of the battery frame102 in FIG. 1.

[0031] A detailed explanation will be given of the specific example inreference to FIG. 1 through FIG. 3 as follows.

[0032] When the battery 101 is attached to inside of the battery frame102, first, in a previously determined direction of inserting thebattery 101, that is, along an arrow mark C direction, one end edgeportion of the battery 101 is inserted into an interval between thenegative electrode terminal 111 and the eaves portion 103 a and 104 a ofthe engaging portions 103 and 104 and is brought into contact with aninner peripheral edge of the battery frame 102 (refer to FIG. 3).

[0033] Under the state, the battery 101 is depressed from above suchthat other end edge portion of the battery 101 is disposed on a lowerside of the eaves portion 109 a of the engaging portion 109. The battery101 is successively brought into contact with the narrow width portions105 c through 108 c of the eaves portions 105 a through 108 a of theengaging portions 105 through 108 and the wide width portions 105 dthrough 108 d, when the battery 101 is further depressed, as shown bybroken lines of FIG. 2, at inside of the battery frame 102, the battery101 is brought to lower sides of the eaves portions 103 a through 109 aof the engaging portions 103 through 109 and the battery 101 iscontained and held at inside of the opening portion 113 of the batteryframe 102.

[0034] At this occasion, since the eaves portions 105 a through 108 aare provided with the tapers, when the battery 101 is contained and heldat inside of the opening portion 113 as described above, by successivelybringing a peripheral edge of the battery 101 into contact with theeaves portions 105 a through 108 a, as shown by bold lines of FIG. 2,the arm portions 105 b through 108 b having elasticity are successivelybent to expand and the eaves portions 105 a through 108 a are alsoexpanded. Thereby, the battery 101 can easily be contained at a holdingportion thereof of FIG. 1 and FIG. 2. The battery 101 is contained andheld at inside of the opening portion 113 of the battery frame 102 and apositive electrode and a negative electrode of the battery 101 arerespectively held in a state of being brought into electrical contactwith the positive electrode terminal 110 and the negative electrodeterminal 111.

[0035] When the battery 101 is held at inside of the opening portion 113of the battery frame 102 in this way, the battery 101 is prevented frombeing positionally shifted in the plane direction by a peripheral wallportion of the battery frame 102 and the arm portions 103 b through 109b of the engaging portions 103 through 109 and prevented from beingpositionally shifted in the sectional direction or detached by the eavesportions 103 a through 109 a. Further, when the battery 101 isinterchanged, the battery 101 can easily be removed by using a tool oftweezers or the like.

[0036] As has been described above, the battery holding structure of anelectronic timepiece according to the specific example of the inventionis characterized particularly in having the battery frame 102 having theopening portion 113 for inserting and holding the battery 101 such asthe button battery, in which the battery frame 102 is formed with theengaging portions 105 through 108 having the eaves portions 105 athrough 108 a projected to the side of the opening portion 113 andprovided with the tapers.

[0037] Therefore, the battery 101 can be held without detachment evenwhen impact such as dropping occurs without using a separate member forrestricting movement of the battery 101 in the sectional direction,further, there is achieved an effect that the mountability of thebattery 101 to the eaves portions 103 a through 109 a projected long tothe side of the opening portion 113, is excellent.

[0038] Further, the structure can be simplified by reducing a number ofparts, further, since a number of integrating steps can be reduced,shortening of a time period of integration and therefore, a reduction incost can be achieved.

[0039] Further, it is not necessary to arrange a part such as a batteryholder to laminate on the battery 101 and therefore, the electronictimepiece can be thinned.

[0040] Furthermore, by integrally molding the battery frame 102 and theeaves portions 103 through 109 by insulating resin, an insulating plateor the like is dispensed with.

[0041] Further, although according to the specific example, the buttonbattery 101 is used as the battery 101, a battery having other shape maybe used. Further, although an explanation has been given of the exampleof the electronic wristwatch, the invention is applicable not only tothe electronic wristwatch of a digital display type or an analog displaytype but also to various electronic timepieces of a battery drive typesuch as a-wall type electronic timepiece, a desk-top type electronictimepiece and so on.

[0042]FIG. 4 is a plane view showing other specific example of a batteryholding structure of an electronic timepiece according to the inventionand FIG. 5 is a front sectional view taken along a line E-E of FIG. 4.Further, in both of the drawings, the same portions are attached withthe same notations and portions the same as those of FIG. 1 through FIG.3 are attached with the same notations. Further, FIG. 4 shows a drawingomitting a case back.

[0043] A difference between the specific example and the specificexample shown in FIG. 1 through FIG. 3, resides in forming projectedportions 501 through 507 integrally with the respective eaves portions103 a through 109 a in order to firmly prevent positional shift in thesectional direction or detachment of the battery 101, the method ofinserting and holding the battery 101 and the like stays the same andtherefore, an explanation will mainly be given of the plurality ofprojected portions 501 through 507 as follows.

[0044] In FIG. 4 and FIG. 5, the respective projected portions 501through 507 are molded by insulating resin and molded integrally withthe respective eaves portions 103 a through 109 a on sides of a caseback 601 of the respective eaves portions 103 a through 109 a. Front endportions of the projected portions 501 through 507 are formed in a shapeof a frustrum of a right circular cone and when the front end portionsare pressed by the base back 601, the front end portions are crushed andpart tolerance can be absorbed. Further, at least portions of theprojected portions 501 through 507 are constituted to project to theside of the opening portion 113 more than inner wall faces 602 of thearm portions 103 b through 109 b of the engaging portions 103 through109 and are constituted to be brought into contact with the case back601 at positions projected to the side of the opening portion 113 morethan the inner wall faces 602. Further, there is constructed aconstitution in which in a state of completing the electronic timepieceby mounting the case back 601 of the electronic timepiece, the case back601 is brought into contact with the projected portions 501 through 507.

[0045] According to the above-described constitution, when the case back601 is mounted to a main body of the electronic timepiece in a state inwhich the battery 101 is contained and held at inside of the openingportion 113 of the battery frame 102, first, the case back 601 isbrought into contact with the projected portions 501 through 507. Underthe state, when the case back 601 is mounted to the main body of theelectronic timepiece, the case back 601 is mounted to the main body ofthe electronic timepiece in a state of pressing the projected portions501 through 507. At this occasion, the projected portions 501 through507 are brought into contact with the case back 601 at the positionsprojected to the side of the opening portion 113 more than the innerwall faces 602 and therefore, the eaves portions 103 a through 109 a arebent in the direction of the battery 101 by press force of the case back601. The battery 101 is solidly held in the state of being pressed bythe eaves portions 103 a through 109 a at inside of the opening portion113 of the battery frame 102.

[0046] Therefore, the specific example not only achieves an effectsimilar to that of the above-described specific example but alsomovement of the battery 101 in the sectional direction can firmly berestricted by the eaves portions 103 a through 109 a and therefore, evenwhen the electronic timepiece undergoes impact as in the case ofdropping the electronic timepiece, the battery 101 can further firmly beprevented from being shifted positionally or detached.

[0047] Further, the projected portions 501 through 507 are brought intocontact with the case back 601 at the positions projected to the side ofthe opening portion 113 more than the inner wall faces 602 andtherefore, the eaves portions 103 a through 109 a can firmly be pressedto the side of the battery 101 and the battery 101 can be held furtherfirmly. Therefore, an electronic timepiece excellent in impactresistance can be constituted.

[0048] Further, it is not necessarily needed to provide the projectedportions 501 through 507 at all of the eaves portions 103 a through 109a but at least three of the projected portions may be arranged withexcellent balance. Further, pluralities of the projected portions 501through 507 may be arranged at the respective eaves portions 103 athrough 109 a. Further, it is also possible to construct a constitutionsuch that the projected portions 501 through 507 are not projected tothe side of the opening portion 113 more than the inner wall faces 602and are brought into contact with the case back 601 at positions atwhich the projected portions 501 through 507 are not projected to theside of the opening portion 113 from the inner wall faces 602. Also inthis case, the arm portions 103 b through 109 b are bent by press forceof the case back 601 to thereby press the eaves portions 103 a through109 a to the battery 101, thereby, the positional shift of the battery101 in the sectional direction is prevented.

[0049] Industrial Applicability

[0050] As described above, the battery holding structure of theelectronic timepiece according to the invention is applicable not onlyto the electronic wristwatch of a digital display type or an analogdisplay type but also to various electronic timepieces of a batterydrive type such as a wall type electronic timepiece, a disk-top typeelectronic timepiece and so on.

1. A battery holding structure of an electronic timepiece characterizedin comprising a battery frame (102) having an opening portion (113) forholding a battery (101), wherein the battery frame (102) is providedwith engaging portions (105 through 108) projected to a side of theopening portion (113) and having eaves portions (105 a through 108 a)provided with tapers.
 2. The battery holding structure of an electronictimepiece according to claim 1, characterized in that a plurality of theengaging portions (105 through 108) are provided and the eaves portions(105 a through 108 a) are provided with the tapers in shapes by whichwhen the battery is attached, the battery (101) is brought into contactwith narrow width portions (105 c through 108 c) of the eaves portions(105 a through 108 a) and thereafter brought into contact with widewidth portions (105 d through 108 d) thereof.
 3. The battery holdingstructure of an electronic timepiece according to claim 2, characterizedin that the engaging portions (105 through 108) are constituted by theeaves portions (105 a through 108 a) and arm portions (105 b through 108b) having an elasticity for attaching the eaves portions (105 a through108 a) to the battery frame (102).
 4. The battery holding structure ofan electronic timepiece according to claim 3, characterized in that thebattery frame (102) and the engaging portions (105 through 108) areintegrally molded by an insulating resin.
 5. The battery holdingstructure of an electronic timepiece according to any one of claims 1through 4, character zed in that the eaves portions (105 a through 108a) are integrally formed with projected portions (501 through 507) whichare brought into contact with a case back (601) in a state of beingmounted with the case back (601).
 6. The battery holding structure of anelectronic timepiece according to claim 5, characterized in that atleast portions of the projected portions (501 through 507) areconstituted to project to the side of the opening portion (113) morethan inner wall faces (602) of the engaging portions (105 through 108)and are brought into contact with the case back (601) at positionsprojected to the side of the opening portion (113) more than the innerwall faces (602).
 7. The battery holding structure of an electronictimepiece according to any one of claims 1 through 6, characterized inthat the battery (101) is a button battery.
 8. The battery holdingstructure of an electronic timepiece according to any one of claims 1through 7, characterized in that the electronic timepiece is anelectronic wristwatch.